Wikipedia states that: In December 2006 Darlington and Stockton Borough Councils approved plans for the first of two expansions for the airport. The plans include an extended and refurbished terminal, with improved baggage handling and check-in facilities, lounges, office space and retail and restaurant facilities. Also, a Cargo and Maintenance “village” is proposed along with nine additional aircraft stands and 4,500 car parking spaces.

A second planning application has also been approved, for an 18,600sq metre business
park with a 100-bed hotel, public house and restaurant. Since these plans were
approved, the airport modified the application replacing the proposed Cargo and
Maintenance “village” with an Industrial Estate instead.

Building work for both of the above plans has yet to commence.

Plans for an 80-bedroom Hotel have been approved, however Durham Tees Valley
Airport opposes these plans as they were made by an outside company.

Analysis of flights, routes, and top 10 destinations from Durham Tees Valley Airport in 2011. Also carbon emissions.
And passenger growth and numbers over the past 15 years. http://www.awsw.co.uk/allco2/MME_co2.html